1. Field of the Invention
The present invention relates to a computer system and a method of controlling battery power. More particularly, the present invention relates to a system and method for simultaneously discharging solar power and charging a system battery.
2. Description of the Related Art
Currently, a solar charging system applied to mobile devices, such as a laptop/notebook/pad computer, supplies power to an adaptor of the mobile device as a separate device. A solar panel having an area larger than the mobile device is typically used. Thus, such a charging system is physically spread out, due to limitations in energy conversion efficiency of a solar cell versus the area.
FIG. 1A illustrates an example of a solar charging system realized independently of a computer system.
The solar charging system 110 in FIG. 1A supplies power to a computer system 100 by discharging energy that has been charged within the charging system. In this example, a high capacity battery, such as high capacity lithium or nickel-cadmium batteries, is necessary to cover a load of the system with a high capacity. The solar charging system 110 serves to replace an alternating current (AC) adaptor until a charged high-capacity battery is entirely discharged.
FIG. 1B illustrates a solar charging system integrated with a computer system as a single unit.
Referring now to FIG. 1B, the solar charging system 120 is realized in a single unit on the rear side of a panel of the computer system 100. The solar charging system 120 uses a restricted charging process whereby a system battery is charged only when the computer system 100 is turned off. Thus, a user has limitations in using such solar charging system 120.
FIG. 2 illustrates a process of charging a system battery by a typical solar charging system.
When inserting an adaptor, a computer system 100 generally uses alternating current (AC) power input through the adaptor prior to using direct current (DC) power input from a battery.
The computer system 100 determines whether a solar battery cell is charged enough to replace AC power (S201) as the current power source. If the solar battery cell is not sufficiently charged enough to replace AC power at S201 (S201-N), the computer system 100 disables a change to a solar charging mode (S212) and returns the current charging mode.
However, if the solar battery cell is sufficiently charged so as to replace AC power (S201-Y), the computer system 100 determines whether it would be able to operate in the solar charging mode (S202). Specifically, in the case receiving an input of DC power instead of AC power, i.e., input with power through the battery instead of the AC adaptor, the computer system 100 can operate in the solar charging mode. If the computer system is not able to operate in the solar charging mode (S202-N), the computer system 100 disables a change to the solar charging mode (S212). If the computer 100 changes to the solar charging mode even if disabling a change to the solar charging mode, the computer system 100 may display a warning light informing of a danger that operability may fail.
However, if being able to operate in the solar charging mode (S202-Y), the computer system 100 enables charging of the system battery (S203). In this case, energy charged in the solar battery cell charges the system battery of the computer system 100 (S204). When the system battery is fully-charged, a charging process is completed.
In order to manage a high load of the computer system 100, a large area of a solar panel is used in order to be able to convert sufficient amounts of solar energy for powering the load. Moreover, in order that a solar pack loads the computer system 100 and re-charges the system battery for a certain amount time, an additional battery pack is needed to operate the computer concurrent with the recharging of the system battery. However, an additional large-size solar pack is inconvenient for a user to carry and may cause serious safety problems when connected to the computer system 100 with a larger capacity than a battery in the solar pack. In addition, the battery in the solar pack and a battery protection device/IC to control the same are necessary, thereby resulting in an increase in the manufacturing cost of the solar pack.